Today, software applications executing in computers, smartphones, etc. or embedded devices generate step-by-step navigation directions. Typically, a user specifies the starting point and the destination, and a software application displays the directions immediately and/or as the user travels from the starting point and the destination. These navigation directions may be inaccurate, however, if they do not account for current conditions such as local road closures.
Recently, many environmentally-conscious cities around the world have implemented rules designed to reduce pollution by limiting the number of vehicles on the road. Each city has implemented these “green” driving restrictions in somewhat different ways. For instance, in some cities, vehicles may be restricted from particular roads based on, e.g., a vehicle license plate number. In particular, vehicles having even-numbered license plate numbers may drive on a given road on even-numbered dates, while vehicles having odd-numbered license plate numbers may drive on that road on odd-numbered dates. In other cities, only vehicles having particular permits are allowed to drive at peak rush time periods. In still other cities, certain types of vehicles are restricted from certain roads. Moreover, in some cities, restrictions may be added or removed on a day-to-day basis based on pollution levels each day.